Biomedical subjects

N Belhacène

Publications and source records attributed to N Belhacène.

2 recordsLinked to original sources

PubMed1998

Differential expression of the Kell blood group and CD10 antigens: two related membrane metallopeptidases during differentiation of K562 cells by phorbol ester and hemin.

The erythroleukemic cell line K562 can undergo further differentiation in erythroid or megakaryocytic lineage depending on the nature of the stimulus. Phorbol ester (PMA) stimulates megakaryocytic development whereas hemin promotes erythroid differentiation of these cells. We have examined the effect of PMA and hemin on the expression of the Kell blood group and CD10 antigens, two related proteins that belong to a family of membrane-bound neutral metalloendopeptidases. We show here that differentiation of K562 cells by PMA in the megakaryocytic lineage results in abolishment of Kell mRNA accumulation and protein expression and, in parallel, the induction of CD10 mRNA accumulation, protein expression, and enzymatic activity. Conversely, differentiation of these cells by hemin in the erythroid lineage is accompanied by an up-regulation of Kell mRNA and protein expression, with no changes in CD10 mRNA and protein expression. Thus, CD10 and Kell can be regarded as specific markers of the differentiation of K562 cells in the megakaryocytic and erythroid lineages, respectively.

Antigens, CD↗

PubMed1997

CD10 plays a specific role in early thymic development.

Development of T lymphocyte is a complex process that depends on both thymocytestromal cell interactions and the production of soluble factors such as cytokines, peptides, and hormones. In many tissues, the concentration of active biological peptides is regulated locally by a specialized family of enzymes: the ectopeptidases. We show here that treatment of fetal thymic organ cultures (FTOC) with the specific CD10 (endopeptidase 24.11) inhibitors SCH 32615: (N-[L-(1-carboxy-2-phenyl)ethyl]-L-phenylalanyl-beta-alanine), RB25: (N-(3-[(hydroaxyamino)carbonyl]-2-benzylidene-1-oxopropyl]-N-glyci ne), and thymopentin (TP5) results in the inhibition of thymocyte differentiation. Each agent induces a significant decrease in the number of double positive (CD4+CD8+) cells in favor of the TN (TcR alpha beta-CD4-CD8-) population. RB25 also blocks T lymphocyte differentiation in FTOC when preinjected into pregnant mice. Finally, RB25 and TP5 were also shown to reduce the number of CD44+CD25- and CD44-CD25- thymocytes both in vitro and after preinjection in vivo in day 2 FTOC. Thus, agents that affect endopeptidase 24.11 activity impair T cell development both in vitro and in vivo. Our results show that the CD10 molecule plays a specific role in promoting early T cell development.

Animals↗